In the inspection by video equipment of a stream of like objects being sequentially transported on a conveyor, it is required that the image processing be done on a real time basis to produce the necessary secondary control signals. Various prior art techniques are disclosed in Ohyama U.S. Pat. No. 4,866,783 and Turcheck et al U.S. Pat. No. 4,784,493.
Composite video signals are not required for some applications. Therefore a raster scan is not essential. It may be sufficient to have a high resolution silhouette of an object elevation to determine the object orientation or size. Real time processing of large amounts of data is prohibitive for a feasible low-cost system due to the processing time involved and huge memory requirements to store all the information customarily used. Usual solutions would be to invest in an expensive, faster computer and to add on the required memory.